A fast, high-granularity silicon multiplicity detector for the NA50 experiment at CERN

We have designed a silicon detector to measure the angular distribution and the multiplicity of charged secondaries produced in high-energy PbPb interactions. It will be used to characterize the events in the NA50 experiment. The experiment will have to function at very high rate, and the silicon detectors will have to operate in the high-radiation area close to the target. ore, the detector will have to be very fast (dead time below 50 ns), radiation resistant (up to the Mrad level as dose and up to more than 1013 particles/cm2 as non-ionizing damage) and of high granularity. The conditions on noise, speed and radiation hardness are comparable to the ones foreseen at the future Large Hadron Collider at CERN. sent here the detector design, discuss some of the solutions which have been investigated and report first results on the components of the system which have been designed and produced up to now.